xref: /openbmc/linux/drivers/video/vgastate.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * linux/drivers/video/vgastate.c -- VGA state save/restore
3  *
4  * Copyright 2002 James Simmons
5  *
6  * Copyright history from vga16fb.c:
7  *	Copyright 1999 Ben Pfaff and Petr Vandrovec
8  *	Based on VGA info at http://www.goodnet.com/~tinara/FreeVGA/home.htm
9  *	Based on VESA framebuffer (c) 1998 Gerd Knorr
10  *
11  * This file is subject to the terms and conditions of the GNU General
12  * Public License.  See the file COPYING in the main directory of this
13  * archive for more details.
14  *
15  */
16 #include <linux/config.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/fb.h>
20 #include <linux/vmalloc.h>
21 #include <video/vga.h>
22 
23 struct regstate {
24 	__u8 *vga_font0;
25 	__u8 *vga_font1;
26 	__u8 *vga_text;
27 	__u8 *vga_cmap;
28 	__u8 *attr;
29 	__u8 *crtc;
30 	__u8 *gfx;
31 	__u8 *seq;
32 	__u8 misc;
33 };
34 
35 static inline unsigned char vga_rcrtcs(void __iomem *regbase, unsigned short iobase,
36 				       unsigned char reg)
37 {
38 	vga_w(regbase, iobase + 0x4, reg);
39 	return vga_r(regbase, iobase + 0x5);
40 }
41 
42 static inline void vga_wcrtcs(void __iomem *regbase, unsigned short iobase,
43 			      unsigned char reg, unsigned char val)
44 {
45 	vga_w(regbase, iobase + 0x4, reg);
46 	vga_w(regbase, iobase + 0x5, val);
47 }
48 
49 static void save_vga_text(struct vgastate *state, void __iomem *fbbase)
50 {
51 	struct regstate *saved = (struct regstate *) state->vidstate;
52 	int i;
53 	u8 misc, attr10, gr4, gr5, gr6, seq1, seq2, seq4;
54 
55 	/* if in graphics mode, no need to save */
56 	attr10 = vga_rattr(state->vgabase, 0x10);
57 	if (attr10 & 1)
58 		return;
59 
60 	/* save regs */
61 	misc = vga_r(state->vgabase, VGA_MIS_R);
62 	gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
63 	gr5 = vga_rgfx(state->vgabase, VGA_GFX_MODE);
64 	gr6 = vga_rgfx(state->vgabase, VGA_GFX_MISC);
65 	seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
66 	seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);
67 
68 	/* force graphics mode */
69 	vga_w(state->vgabase, VGA_MIS_W, misc | 1);
70 
71 	/* blank screen */
72 	seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
73 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
74 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 | 1 << 5);
75 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
76 
77 	/* save font at plane 2 */
78 	if (state->flags & VGA_SAVE_FONT0) {
79 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x4);
80 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
81 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x2);
82 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
83 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
84 		for (i = 0; i < 4 * 8192; i++)
85 			saved->vga_font0[i] = vga_r(fbbase, i);
86 	}
87 
88 	/* save font at plane 3 */
89 	if (state->flags & VGA_SAVE_FONT1) {
90 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x8);
91 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
92 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x3);
93 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
94 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
95 		for (i = 0; i < state->memsize; i++)
96 			saved->vga_font1[i] = vga_r(fbbase, i);
97 	}
98 
99 	/* save font at plane 0/1 */
100 	if (state->flags & VGA_SAVE_TEXT) {
101 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x1);
102 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
103 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x0);
104 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
105 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
106 		for (i = 0; i < 8192; i++)
107 			saved->vga_text[i] = vga_r(fbbase, i);
108 
109 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x2);
110 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
111 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x1);
112 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
113 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
114 		for (i = 0; i < 8192; i++)
115 			saved->vga_text[8192+i] = vga_r(fbbase + 2 * 8192, i);
116 	}
117 
118 	/* restore regs */
119 	vga_wattr(state->vgabase, 0x10, attr10);
120 
121 	vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, seq2);
122 	vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, seq4);
123 
124 	vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, gr4);
125 	vga_wgfx(state->vgabase, VGA_GFX_MODE, gr5);
126 	vga_wgfx(state->vgabase, VGA_GFX_MISC, gr6);
127 	vga_w(state->vgabase, VGA_MIS_W, misc);
128 
129 	/* unblank screen */
130 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
131 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 & ~(1 << 5));
132 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
133 
134 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1);
135 }
136 
137 static void restore_vga_text(struct vgastate *state, void __iomem *fbbase)
138 {
139 	struct regstate *saved = (struct regstate *) state->vidstate;
140 	int i;
141 	u8 misc, gr1, gr3, gr4, gr5, gr6, gr8;
142 	u8 seq1, seq2, seq4;
143 
144 	/* save regs */
145 	misc = vga_r(state->vgabase, VGA_MIS_R);
146 	gr1 = vga_rgfx(state->vgabase, VGA_GFX_SR_ENABLE);
147 	gr3 = vga_rgfx(state->vgabase, VGA_GFX_DATA_ROTATE);
148 	gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
149 	gr5 = vga_rgfx(state->vgabase, VGA_GFX_MODE);
150 	gr6 = vga_rgfx(state->vgabase, VGA_GFX_MISC);
151 	gr8 = vga_rgfx(state->vgabase, VGA_GFX_BIT_MASK);
152 	seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
153 	seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);
154 
155 	/* force graphics mode */
156 	vga_w(state->vgabase, VGA_MIS_W, misc | 1);
157 
158 	/* blank screen */
159 	seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
160 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
161 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 | 1 << 5);
162 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
163 
164 	if (state->depth == 4) {
165 		vga_wgfx(state->vgabase, VGA_GFX_DATA_ROTATE, 0x0);
166 		vga_wgfx(state->vgabase, VGA_GFX_BIT_MASK, 0xff);
167 		vga_wgfx(state->vgabase, VGA_GFX_SR_ENABLE, 0x00);
168 	}
169 
170 	/* restore font at plane 2 */
171 	if (state->flags & VGA_SAVE_FONT0) {
172 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x4);
173 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
174 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x2);
175 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
176 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
177 		for (i = 0; i < 4 * 8192; i++)
178 			vga_w(fbbase, i, saved->vga_font0[i]);
179 	}
180 
181 	/* restore font at plane 3 */
182 	if (state->flags & VGA_SAVE_FONT1) {
183 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x8);
184 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
185 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x3);
186 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
187 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
188 		for (i = 0; i < state->memsize; i++)
189 			vga_w(fbbase, i, saved->vga_font1[i]);
190 	}
191 
192 	/* restore font at plane 0/1 */
193 	if (state->flags & VGA_SAVE_TEXT) {
194 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x1);
195 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
196 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x0);
197 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
198 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
199 		for (i = 0; i < 8192; i++)
200 			vga_w(fbbase, i, saved->vga_text[i]);
201 
202 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x2);
203 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
204 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x1);
205 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
206 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
207 		for (i = 0; i < 8192; i++)
208 			vga_w(fbbase, i, saved->vga_text[8192+i]);
209 	}
210 
211 	/* unblank screen */
212 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
213 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 & ~(1 << 5));
214 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
215 
216 	/* restore regs */
217 	vga_w(state->vgabase, VGA_MIS_W, misc);
218 
219 	vga_wgfx(state->vgabase, VGA_GFX_SR_ENABLE, gr1);
220 	vga_wgfx(state->vgabase, VGA_GFX_DATA_ROTATE, gr3);
221 	vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, gr4);
222 	vga_wgfx(state->vgabase, VGA_GFX_MODE, gr5);
223 	vga_wgfx(state->vgabase, VGA_GFX_MISC, gr6);
224 	vga_wgfx(state->vgabase, VGA_GFX_BIT_MASK, gr8);
225 
226 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1);
227 	vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, seq2);
228 	vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, seq4);
229 }
230 
231 static void save_vga_mode(struct vgastate *state)
232 {
233 	struct regstate *saved = (struct regstate *) state->vidstate;
234 	unsigned short iobase;
235 	int i;
236 
237 	saved->misc = vga_r(state->vgabase, VGA_MIS_R);
238 	if (saved->misc & 1)
239 		iobase = 0x3d0;
240 	else
241 		iobase = 0x3b0;
242 
243 	for (i = 0; i < state->num_crtc; i++)
244 		saved->crtc[i] = vga_rcrtcs(state->vgabase, iobase, i);
245 
246 	vga_r(state->vgabase, iobase + 0xa);
247 	vga_w(state->vgabase, VGA_ATT_W, 0x00);
248 	for (i = 0; i < state->num_attr; i++) {
249 		vga_r(state->vgabase, iobase + 0xa);
250 		saved->attr[i] = vga_rattr(state->vgabase, i);
251 	}
252 	vga_r(state->vgabase, iobase + 0xa);
253 	vga_w(state->vgabase, VGA_ATT_W, 0x20);
254 
255 	for (i = 0; i < state->num_gfx; i++)
256 		saved->gfx[i] = vga_rgfx(state->vgabase, i);
257 
258 	for (i = 0; i < state->num_seq; i++)
259 		saved->seq[i] = vga_rseq(state->vgabase, i);
260 }
261 
262 static void restore_vga_mode(struct vgastate *state)
263 {
264 	struct regstate *saved = (struct regstate *) state->vidstate;
265 	unsigned short iobase;
266 	int i;
267 
268 	vga_w(state->vgabase, VGA_MIS_W, saved->misc);
269 
270 	if (saved->misc & 1)
271 		iobase = 0x3d0;
272 	else
273 		iobase = 0x3b0;
274 
275 	/* turn off display */
276 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE,
277 		 saved->seq[VGA_SEQ_CLOCK_MODE] | 0x20);
278 
279 	/* disable sequencer */
280 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x01);
281 
282 	/* enable palette addressing */
283 	vga_r(state->vgabase, iobase + 0xa);
284 	vga_w(state->vgabase, VGA_ATT_W, 0x00);
285 
286 	for (i = 2; i < state->num_seq; i++)
287 		vga_wseq(state->vgabase, i, saved->seq[i]);
288 
289 
290 	/* unprotect vga regs */
291 	vga_wcrtcs(state->vgabase, iobase, 17, saved->crtc[17] & ~0x80);
292 	for (i = 0; i < state->num_crtc; i++)
293 		vga_wcrtcs(state->vgabase, iobase, i, saved->crtc[i]);
294 
295 	for (i = 0; i < state->num_gfx; i++)
296 		vga_wgfx(state->vgabase, i, saved->gfx[i]);
297 
298 	for (i = 0; i < state->num_attr; i++) {
299 		vga_r(state->vgabase, iobase + 0xa);
300 		vga_wattr(state->vgabase, i, saved->attr[i]);
301 	}
302 
303 	/* reenable sequencer */
304 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x03);
305 	/* turn display on */
306 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE,
307 		 saved->seq[VGA_SEQ_CLOCK_MODE] & ~(1 << 5));
308 
309 	/* disable video/palette source */
310 	vga_r(state->vgabase, iobase + 0xa);
311 	vga_w(state->vgabase, VGA_ATT_W, 0x20);
312 }
313 
314 static void save_vga_cmap(struct vgastate *state)
315 {
316 	struct regstate *saved = (struct regstate *) state->vidstate;
317 	int i;
318 
319 	vga_w(state->vgabase, VGA_PEL_MSK, 0xff);
320 
321 	/* assumes DAC is readable and writable */
322 	vga_w(state->vgabase, VGA_PEL_IR, 0x00);
323 	for (i = 0; i < 768; i++)
324 		saved->vga_cmap[i] = vga_r(state->vgabase, VGA_PEL_D);
325 }
326 
327 static void restore_vga_cmap(struct vgastate *state)
328 {
329 	struct regstate *saved = (struct regstate *) state->vidstate;
330 	int i;
331 
332 	vga_w(state->vgabase, VGA_PEL_MSK, 0xff);
333 
334 	/* assumes DAC is readable and writable */
335 	vga_w(state->vgabase, VGA_PEL_IW, 0x00);
336 	for (i = 0; i < 768; i++)
337 		vga_w(state->vgabase, VGA_PEL_D, saved->vga_cmap[i]);
338 }
339 
340 static void vga_cleanup(struct vgastate *state)
341 {
342 	if (state->vidstate != NULL) {
343 		struct regstate *saved = (struct regstate *) state->vidstate;
344 
345 		if (saved->vga_font0)
346 			vfree(saved->vga_font0);
347 		if (saved->vga_font1)
348 			vfree(saved->vga_font1);
349 		if (saved->vga_text)
350 			vfree(saved->vga_text);
351 		if (saved->vga_cmap)
352 			vfree(saved->vga_cmap);
353 		if (saved->attr)
354 			vfree(saved->attr);
355 		kfree(saved);
356 		state->vidstate = NULL;
357 	}
358 }
359 
360 int save_vga(struct vgastate *state)
361 {
362 	struct regstate *saved;
363 
364 	saved = kmalloc(sizeof(struct regstate), GFP_KERNEL);
365 	if (saved == NULL)
366 		return 1;
367 	memset (saved, 0, sizeof(struct regstate));
368 	state->vidstate = (void *)saved;
369 
370 	if (state->flags & VGA_SAVE_CMAP) {
371 		saved->vga_cmap = vmalloc(768);
372 		if (!saved->vga_cmap) {
373 			vga_cleanup(state);
374 			return 1;
375 		}
376 		save_vga_cmap(state);
377 	}
378 
379 	if (state->flags & VGA_SAVE_MODE) {
380 		int total;
381 
382 		if (state->num_attr < 21)
383 			state->num_attr = 21;
384 		if (state->num_crtc < 25)
385 			state->num_crtc = 25;
386 		if (state->num_gfx < 9)
387 			state->num_gfx = 9;
388 		if (state->num_seq < 5)
389 			state->num_seq = 5;
390 		total = state->num_attr + state->num_crtc +
391 			state->num_gfx + state->num_seq;
392 
393 		saved->attr = vmalloc(total);
394 		if (!saved->attr) {
395 			vga_cleanup(state);
396 			return 1;
397 		}
398 		saved->crtc = saved->attr + state->num_attr;
399 		saved->gfx = saved->crtc + state->num_crtc;
400 		saved->seq = saved->gfx + state->num_gfx;
401 
402 		save_vga_mode(state);
403 	}
404 
405 	if (state->flags & VGA_SAVE_FONTS) {
406 		void __iomem *fbbase;
407 
408 		/* exit if window is less than 32K */
409 		if (state->memsize && state->memsize < 4 * 8192) {
410 			vga_cleanup(state);
411 			return 1;
412 		}
413 		if (!state->memsize)
414 			state->memsize = 8 * 8192;
415 
416 		if (!state->membase)
417 			state->membase = 0xA0000;
418 
419 		fbbase = ioremap(state->membase, state->memsize);
420 
421 		if (!fbbase) {
422 			vga_cleanup(state);
423 			return 1;
424 		}
425 
426 		/*
427 		 * save only first 32K used by vgacon
428 		 */
429 		if (state->flags & VGA_SAVE_FONT0) {
430 			saved->vga_font0 = vmalloc(4 * 8192);
431 			if (!saved->vga_font0) {
432 				iounmap(fbbase);
433 				vga_cleanup(state);
434 				return 1;
435 			}
436 		}
437 		/*
438 		 * largely unused, but if required by the caller
439 		 * we'll just save everything.
440 		 */
441 		if (state->flags & VGA_SAVE_FONT1) {
442 			saved->vga_font1 = vmalloc(state->memsize);
443 			if (!saved->vga_font1) {
444 				iounmap(fbbase);
445 				vga_cleanup(state);
446 				return 1;
447 			}
448 		}
449 		/*
450 		 * Save 8K at plane0[0], and 8K at plane1[16K]
451 		 */
452 		if (state->flags & VGA_SAVE_TEXT) {
453 			saved->vga_text = vmalloc(8192 * 2);
454 			if (!saved->vga_text) {
455 				iounmap(fbbase);
456 				vga_cleanup(state);
457 				return 1;
458 			}
459 		}
460 
461 		save_vga_text(state, fbbase);
462 		iounmap(fbbase);
463 	}
464 	return 0;
465 }
466 
467 int restore_vga (struct vgastate *state)
468 {
469 	if (state->vidstate == NULL)
470 		return 1;
471 
472 	if (state->flags & VGA_SAVE_MODE)
473 		restore_vga_mode(state);
474 
475 	if (state->flags & VGA_SAVE_FONTS) {
476 		void __iomem *fbbase = ioremap(state->membase, state->memsize);
477 
478 		if (!fbbase) {
479 			vga_cleanup(state);
480 			return 1;
481 		}
482 		restore_vga_text(state, fbbase);
483 		iounmap(fbbase);
484 	}
485 
486 	if (state->flags & VGA_SAVE_CMAP)
487 		restore_vga_cmap(state);
488 
489 	vga_cleanup(state);
490 	return 0;
491 }
492 
493 #ifdef MODULE
494 int init_module(void) { return 0; };
495 void cleanup_module(void) {};
496 #endif
497 
498 EXPORT_SYMBOL(save_vga);
499 EXPORT_SYMBOL(restore_vga);
500 
501 MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
502 MODULE_DESCRIPTION("VGA State Save/Restore");
503 MODULE_LICENSE("GPL");
504 
505